Laterally flexible conveyor



July 14, 1970 R. E. THOMSON 3,520,393

LATERALLY FLEXIBLE CONVEYOR Filed Nov. 30, 1967 W FT--,, '22.. 2 Hi1 M M "11:: am; 22

H b I l. t w M W IH Ill! / 22 INVENTOR as RONALD E. THOMSON II 42/ I BY W 4 I ATTORNEYS United States Patent 3,520,398 LATERALLY FLEXIBLE CONVEYOR Ronald E. Thomson, Big Bend, Wis., assignor to Rex Chainbelt Inc., Milwaukee, Wis., a corporation of WIS- cousin Filed Nov. 30, 1967, Ser. No. 687,000 Int. Cl. B65g 15/30 US. Cl. 198-195 ABSTRACT OF THE DISCLOSURE A laterally flexible fiat top conveyor chain includes a plurality of pivotally connected stamped sheet metal links with knuckles curled from the sheet metal for hinge pins. A pin opening in a central knuckle allows for pivotal movement of the pin to accommodate lateral flexing of the link. A tongue of a sheet metal blank from WhlCh the knuckle is formed has metal removed from the sides and ends by cold forming or swaging before it is formed into the knuckle, the removed metal allowing for the lateral pivotal movement of the pin.

BACKGROUND OF INVENTION Field of invention This invention relates to improvements in laterally flexible flat top article carrying conveyors and particularly to an improved construction of metal form ng a central knuckle opening in each conveyor link which allows pivotal movement of connecting pins.

Description of the prior art Laterally flexible fiat top conveyors are known in the prior art. When such conveyors are formed of ad acent links having interconnecting hinge pins, each pin must be able to pivot with regard to the opening in a central knuckle of each adjacent link in order to accommodate the flexing of the flat top links. With conveyor links formed of plastic, this can be accomplished by molding the knuckle opening which is wider at the ends than at the center. However, plastic links are not suitable for many applications and have much less strength than metal links stamped from relatively heavy gauge sheet metal.

In the prior art of laterally flexible flat top conveyors, it was not possible to provide an optimum central knuckle opening for allowing pivotal movement of the pin while still retaining strength in the conveyor. One prior art central knuckle opening formation was merely an elongated opening formed by curling an elongated tongue of a sheet metal blank. This allows unnecessary looseness n the interconnection of the hinge pin and link. Also, chaln tension may cause the chain to twist where the chain is flexed laterally and to lift from the supporting means.

SUMMARY OF THE INVENTION This invention provides for the selective removal of metal from the central knuckle of a stamped sheet metal link by cold coining or swaging the tongue before it 18 curled to form the knuckle. Such cold coining or swaging also increases the fatigue strength of the curled knuckle. Additionally, the removal of material from the sides of the tongue prevents bulging or bell mouthing of the material of the tongue when the tongue is curled.

BRIEF DESCRIPTION 'OF THE DRAWING FIG. 1 is a top plan view of a conveyor having several interconnected flat top links of this invention shown operating over a curved path.

FIG. 2 is a bottom plan view of a single uncurled link blank after cold coining and prior to trimming and curl- 3 Claims I 'ice FIG. 3 is an enlarged bottom plan view of a central tongue of the link showing in detail the facets and bevels formed therein.

FIG. 4 is a further enlarged end view of the tongue.

FIG. 5 is a side elevation view of a formed link.

FIG. 6 is a sectional view taken along 6-6 of FIG. 5.

FIG. 7 is a sectional view taken along line 7-7 of FIG. 5.

DESCRIPTION OF PREFERRED EMBODIMENT The laterally flexible flat top conveyor chain 10 of this invention comprises the series of interconnected links 12 and is supported and guided on suitable wear strips or guides 14 as is known in the art. The adjacent dimensions of the links are such that travel in a curved path is allowed as shown and as will be described.

Each link has a fiat top 16 of substantial area, a central knuckle 18 which is at the front or rear side of the link depending on the direction of its travel, and the pair of spaced knuckles 20 at the other side of the link. The knuckles 20 are spaced apart a distance only slightly greater than the width of knuckle 18 so that the knuckles of adjacent links inter-fit as shown. A pin 22 has its ends secured in knuckles 20 of each link and is rotatable within the knuckle 18 of the adjacent link.

FIG. 2 shows a blank 12:: from which each link 12 is formed. Blank 12a includes a tongue 18a extending from one side for curling to form the central knuckle 18 and tongues 20a extending from the other side for curling to form knuckles 20. The curling by metal working machines is well known in the art and must provide knuckles of uniform outer dimensions so as to fit properly the drive sprocket, not shown, by which the conveyor is driven.

According to the present invention, tongue 18a before curling is formed by cold working or swaging to provide a number of facets and bevels on the side thereof which when curled forms the inside of knuckle 18. These facets or bevels provide the clearance within the knuckle which is required as described and include facets 36 and 38 defining the center line 40 at the end of the tongue and side bevels 42 and 44. There may also be intermediate facets 46 and 48. After forming these facets or bevels by swaging, the extra material 50 is trimmed prior to curling tongue 18a to form knuckle 18. It is noted that the side bevels 42 and 44 are spaced a significant distance from the center and are adjacent the sides so that there is a large surface area 52 in the center of the tongue.

The facets 36 and 38 are shown in section in FIGS. 6 and 7 and allow the pin 22 to pivot about a vertical central axis a while resting on one facet and an opposed bevel such as facet 38 and bevel 42. These flat surfaces are coordinated with the maximum turn of the conveyor and aid in holding and aligning the pins 22. Further, when the conveyor is in a straight line, the force of the pin will be on flat surface 52 which is of an extensive area and further aids in self-alignment.

Furthermore, the facets and edge bevels help in the curling with present equipment and facets 46 and 48 make the knuckle opening 32 appear around when viewed from the side as in FIG. 5. The swaging and cold coining adds strength and increases the resistance of the tongue to uncurling. Importantly, the cold working of the metal forming the inside corners of knuckle prevents or retards fatigue cracking of the metal. The removal of material at the sides by the bevel prevents bell mouthing of the tongues as they are curled.

While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. In a conveyor chain of the fiat top type comprising: a series of links having interfitting knuckles with aligned pin openings which contain connecting pins for holding the the adjacent interfitting knuckles together, each being for adjacent interfitting knuckles together, each being formed of fiat blank sheet metal and having a central tongue and oppositely extending spaced apart tongues, said central tongue and said spaced apart tongues being curled to form said pin openings, said central tongue having cold coined swaged facets on one surface thereof extending inwardly from the side edge such that in the curled position said facts provide an enlarged opening and bearing surfaces for said pin which permits lateral pivotal movement of adjacent links about and axis extending perpendicular to the plane of the flat top conveyor chain.

2. In a conveyor chain as set forth in claim 1 wherein said cold coined swaged facts which extend inwardly from the side edges of said central tongue stop short of the center of the tongue to thereby define a central flat bearing surface for said connecting pin when the axis of said connecting pin is parallel to the center line of said pin openmg.

3. In a conveyor chain as set forth in claim 2 wherein said cold coined swaged facets extend inwardly from the end of said central tongue to provide a bearing surface for said connecting pin when the axis of said connecting pin is pivoted with respect to' the center line of said pin opening.

References Cited UNITED STATES PATENTS 1,945,357 1/1934 Pierce 198-189 2,660,292 11/1953 Cheeseman 198-189 FOREIGN PATENTS 917,688 Great Britain.

RICHARD E. AEGERTER, Primary Examiner Patent No. 398 Dat d July 14, 1970 Inventor(s) Ronald E. Thomson It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 13 the first word "facts" should read --facets-- line 18 after "swaged" and before "which" the word "facts" should read --facets--.

Signed and sealed this Lrth day of May 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, JR. Attesting Officer Commissioner of Patents FORM 90-1050 (10-69) uscomwoc wan-ps9 i U 5 GOVERNMENT 'RINIING OFFICE I!!! O-JOl-lll 

